Spirometer



C. LANOOY SPIROMETER June 3, 1958 Filed odt. 29, 1953 INVENTOR CORNELIS LANOOY AGENT United SPIROMETER Application October 29, 1953, Serial No. 388,952

Claims priority, application Netherlands November 25, 1952 8 Claims. (Cl. 128-208) This invention relates to a spirometer for recording the respirations of a patients lungs.

The principal object of the invention is to provide an improved apparatus for measuring and recording the exact amount of air expelled from a patients lungs throughout the entire or fractional period of time required for an exhalation.

An additional object of the invention is to provide an apparatus by which the timing of an exhalation is comrnenced by merely introducing the exhaled breath into the spirometer.

A further object is to provide a construction so that the apparatus is readily portable and conveniently and automatically records a linear curve showing the relationship between the amount of breath expelled and the duration of time required therefor.

The above and other features, objects and advantages of the present invention will be fully understood from the following description considered in connection with the accompanying illustrative drawing which is a sectional side view of a spirometer according to the invention.

In the drawing, a detachable closure member 2 is secured to a cylindrical drum 1. Closure member 2 has an adapting edge 3 carrying cams 4 which can rotate about bolts 5. Drum 1 has a recess 6 for engaging cams 4 upon placement of closure member 2 on drum 1. Closure member 2 is secured in place by milled ring 7 which has a limited rotation to which the cams 4 are secured by means of bolts 5. Closure member 2 also includes fan 8 and magnetic brake 9, the latter being rigidly arranged in closure member 2. Fan 8 is rotatably mounted on a shaft which has one of its ends journalled in aperture 11 and the other end journalled through magnetic brake 9. Vanes 10 are also supported in aperture 11 adjacent fan 8. The shaft 10 is coupled by means of a transmission system 12 to an indexing member 13 which has a square shape. Closure member also includes exhaust apertures 14 through which air can escape. Drum 1 contains a frame constituted by a member 15, two guides 16, which are rigidly secured therein, and member 17 in which guides 16 are also rigidly secured. Lever 24) is secured to recording stud 19 and one end of spring 21 is connected to lever 29 and the other end of spring 21 is connected to member 18. Drum 1 also contains a guide shaft 22 about which members and 18 are rotatably journalled. Member 18 is provided with a roller bearing which engages shaft 22. A timing mechanism such as a clock 23 is provided in the lower part of drum 1. The movement of the output shaft of clock 23 is transferred to disc 25 which includes a centrally disposed square pin 26 for winding the timing mechanism. Flexible tube 27 which has a tightly wound helical form is secured to disc 25 at a point 28, Wound on the peripheral guide portion of disc 25, and slidably mounted on shaft 22. The shaft 22 is located inside tube 27 and is concentrically spaced from the peripheral guide of disc 25 so as to provide a slight res Patent 9 2,837,083 Patented June 3, 1958 clamping action to flexible tube 27. The shaft 22 is immovable and serves as a guide for tube 27 which slides up and down shaft 22 when the timing mechanism is either wound up or run down. The recording member 18 is rotatably secured to the tube 27 and in order to ensure small frictional losses, the member 17 is also 7 provided with a ball-bearing. Disc 25 has a cam 29 which is so positioned that, when the recording member has reached the upper end of guides 16, the cam moves a lever 30 which causes the clockwork 23 to be stopped. The members 15 and 17 carry earns 31 and 32 which can co-operate with the lever 20 in such a manner that, when the recording member 18 has reached its upper position, the recording stud 19 is tilted so as to no longer engage the inner side of the drum 1, whereas in the lower position of the recording member 18, the cam 32 moves the recording stud 19 back into the recording position. A recording sheet may be provided on the inner side of the drum 1. If the recording sheet consists of prepared paper, a metallic recording stud 19 will be selected which permits a record to be made on this paper. The recording sheet may also consist of ordinary paper, and in this case the recording stud 19 has an ink container. In the latter case, as shown, the recording member 18 has a pin 33 secured to it which pierces and cleans the fine aperture of the recording stud 19 when the stud is not in engagement with the paper. The ink container may also be filled in this position.

The operation of the described spirometer is as follows: The closuremember 2 is removed from the drum 1, the milled ring 7 being turned such that cams 4 do not engage recess 6. Subsequently, a sheet of recording paper is placed on the inner side of the drum 1, with the printed side remote from the wall. This is a simple operation, since the recording member 18 occupies its upper position and hence the recording stud 19 is tilted and does not engage the wall of the drum 1. The paper may be provided with a mark which must correspond to a mark provided on the member 15, so that the printed paper is correctly positioned. Subsequently, the clockwork is wound up by means of a key placed on the square member 26, so that the tube 27 is wound on the disc 25 and the recording member 18, together with recording stud 19, which is taken along by the tube 27, is moved into its lower position. When the lower position is reached, the cam 32 engages the lever 20, so that the recording stud 19 is tilted and caused to engage the paper by the action of spring 21. Now, the closing piece 2 is secured to the drum 1 by slightly turning the milled edge 7, the locating member 13 indexes all movable parts which assume the correct positions for using the device. A mouthpiece is then inserted into aperture 11. The patient places his mouth on the mouthpiece and while holding the device in his hands, if desired, rapidly expires his breath into the device. As soon as the blade wheel 3 starts its rotation, so that the frame 16 and the recording member 18 also start to rotate, the clockwork 23 is also started due to the rotation of the member 17. The recording member 18, together with the recording stud 19, is not only caused to make a rotational movement, due to the rotation of the blade wheel, but also to move upwards because the tube 27 winds off the disc 25 along the shaft 22 and moves upwards. The upward movement has a linear relationship with time, Whereas the rotational movement, inter alia due to the presence of the braking disc 9, has a linear relationship with the amount of air that is blown in. Consequently, a curve is drawn on the recording sheet, the abscissae being a linear indication of time and ordinates a linear indication of the amount of air. The curve immediately shows, for example, the total content of the lungs, the time in which a certain portion of the contents of the lungs is 3 expired and other data, so that the attending physician can immediately draw his conclusions. When the recording member 18 has reached its upper position, which may be the case, for example, four seconds after the clockwork has started, the cam 29 abuts against the lever 30, so that the clockwork is stopped. At the same time, the cam 31 urges against the lever 2i), the recording stud 19 being tilted, removed from the paper, and moved into a position in which the fine aperture of the recording stud is pierced and cleaned by the needle 33. The recording has then ended and the sheet of paper may be taken out of the drum 1 after the closing cap 2 has bee removed.

An advantage of the spirometer according to the invention resides in the fact that a physician may readily carry the device in his pocket. This construction is particularly desirable because voluminous bellows which spring leaks are not used and liquids are not used. Manipulations other than inserting the paper, providing the mouth-piece and winding up the clockwork are not required, since the expiration of the person to be examined operates the spirometer. Moreover, a Tifieneaucurve is recorded, representing all necessary data in linear relationship, upon completion of the exhalation. The instrument may be held by the patient himself and is comparatively light in weight. The paper is automatically held against the inner side of the drum due to its natural resilience.

In a spirometer according to the embodiment described, the transmission ratio between the blade wheel and the locating member 13 is l to 289. One filling of the recording stud with red recording ink provided from 20 to 30 curves, and the time elapsed between two recordings was approximately 30 seconds. The described spirometer is also particularly suited for mass examinations in combination with periodic X-ray screening tests.

What is claimed is:

l. A spirometer comprising a housing, a detachable closure including a mouthpiece therein mounted on said housing, a first rotatable member mounted within said housing adjacent said mouthpiece and being rotatable by air currents conducted through said mouthpiece and said member, a second rotatable member operably connected to and rotated by said first member, an indicating device on said second member and mounted for sliding movement, a timing mechanism operably connected to said indicating device to slide said indicating device on said second member, and means for commencing the sliding movement of said indicating member when an air current starts to rotate said first member.

2. A spirometer as claimed in claim 1 in which transmission gears connect said first rotatable member to said second rotatable member, and the indicating de- Vice is mounted on said second rotatable member so that the direction of rotation and sliding movements are at an angle to one another.

3. A spirometer comprising a housing, a detachable closure including a mouthpiece therein mounted on said housing, a first rotatable member mounted within said housing adjacent said mouthpiece and being rotatable by aircurrents conducted through said mouthpiece and said member, a shaft mounted in said housing, a frame mounted on said shaft and being rotatable around the axis thereof, an indicating device being mounted on said frame for sliding movement in the axial direction of said shaft, said frame being operably connected to and rotated by said first member, a timing mechanism mounted adjacent said frame, a flexible tube connected at one end with said indicating device and at the other end with said timing mechanism, and means for placing said indicating device in position for recording the amount of air expelled during a period of time.

4. A spirometer as claimed in claim 3 in which a disc having a peripheral guide is rotatably connected to said timing mechanism, and said flexible tube is wound on said guide.

5. A spirometer as claimed in claim 4 in which a locking member is mounted in said housing and connected to said frame and said timing mechanism, said locking member being responsive to the rotation of said frame to begin the operation of said timing mechanism, and said disc having a. pin thereon engageable with said locking member to stop the operation of said timing mechanism.

6. A spirometer as claimed in claim 5 in which a magnetic braking disc is mounted in said housing adjacent,

said first rotatable member in order to provide a linear relationship between the rotary and sliding movements of the indicating device.

7. A spirometer as claimed in claim 6 in which a locating member is secured to said first rotatable member to properly index its connection with said frame.

8. A spirometer as claimed in claim 7 in which a chart is positioned on the inner wall of said housing, and a recording pen secured to said indicating member and being engageable with said chart, said pen having an engaged position in which said pen touches said chart and a disengaged position in which said pen is removed from said chart.

References Cited in the file of this patent UNITED STATES PATENTS 2,155,136 Langdon Apr. 18, 1939 2,427,145 Koehler Sept. 9, 1947 2,593,285 Fay et al. Apr. 15, 1952 

